docs: def _load_model(self, dct):
          """Load a serialized PyPhi model.
  
          The object is memoized for reuse elsewhere in the object graph.
          """
          classname, version, _ = _pop_metadata(dct)
  
          _check_version(version)
          cls = self._models[classname]
  
          # Use `from_json` if available
          if hasattr(cls, 'from_json'):
              return cls.from_json(dct)
  
          # Default to object constructor
          return cls(**dct)